摘要
通过对空泡水筒中螺旋桨进行空泡噪声测量试验,采集了螺旋桨在空化条件和非空化条件下的噪声信号。借助数字信号处理技术对声信号进行频谱分析,研究空泡噪声特征信号在频域的特征和规律,以便判别或预报这类空泡及其噪声特性。此次试验特别引入加速度计,测量了螺旋桨动力仪引起的机械振动信号,并得出其信号对水听器采集的水声信号影响较大,可采用噪声消除方法降低干扰。试验表明,噪声频率在高频时空化噪声比非空化噪声声功率级增加约20 dB。另外,详细介绍了噪声测量系统和测试方法,同时也采用高速摄像机对螺旋桨空泡进行了观测。
This paper investigates the cavitation and non-cavitation noises produced by propellers based on a water tunnel experiment. The power spectrum of the noise is first analyzed through digital signal pro- cessing technologies, where the frequency features and regular patterns of the cavitation noise signal are obtained for forecasting purposes. Particularly, the accelerometers are employed during the experiment to measure the mechanical vibration signal, which reveals its severe interference on the underwater acoustic signal. Thus, a noise reduction procedure is applied to reduce the external noise. The results show that at high frequencies, the sound power level under the cavitating flow condition is 20 dB higher than that under the non-cavitating flow condition. Aside from these observations, the cavitation behavior of the propeller is examined with the help of high-speed cameras, while the measuring system and methods are also dis- cussed in detail.
出处
《中国舰船研究》
2013年第1期84-89,共6页
Chinese Journal of Ship Research
基金
国家自然科学基金资助项目(51009145)
关键词
空泡水筒
空泡噪声
高速摄像机
空泡观察
cavitation tunnel
cavitation noise
high-speed camera
cavitation observation
